The plantar fascia is a piece of tissue in your foot that connects the front of the foot to your heel. It's designed to absorb the high stresses and strains we place on our feet. When this tendon becomes irritated and inflamed, it is known as plantar fasciitis. Plantar fasciitis is one of the most common causes of heel pain. Plantar fasciitis can very painful and pain and stiffness can be typically felt along the bottom of the foot near the heel. It can feel very sharp to very dull and vary. Some patients also report a burning feeling.